June 5, 2010

Cap Wars. RCA Caps Shoot Out. Cardas vs Telos vs Generic.

Un used RCA inputs and outputs on all our hifi equipment acts like a mini antenna for picking up stray RFI and EMI interference. Or so it seems, as it has been a source of endless online debates from the camps of objectivist and subjectivist. Between those who swear by the sonic results they heard and others who seemed indifferent. I referred the subject matter to my very good friend Felix, whose pair of ears, I consider most golden amongst the gold standard. Felix was help full enough to show me the way and how to measure for the minute differences when an RCA cap is inserted on to an un used RCA input/output. We found that the measured difference was just like 0.002 - 0.004mv(miliwatts) less conductivity within an RCA when covered by a cap instead of being left exposed. The million dollar question raised, by the objectivist among my audiophile buddies is, can we hear the said milliwatt difference in measurement? Are our ears really that sensitive? Or are we just being psycho acoustic?

I can't answer any of those questions, all I know is that there is a measure able difference, and I could hear the difference. That alone is all the proof I need, psycho acoustic or otherwise! For everyone else, I cannot help to make up your mind on your behalf, so you'll just need to try it, and decide for yourself .
Top: Telos gold(left) and platinum(right).
Bottom: Cardas(left) and nickel coated generic caps(right).

Telos on top row, note teflon insulation. Cardas(bottom left) and nickel coated generic(bottom right) caps does not have insulation. Note the similar design but the sound is not even closely related.

The Telos RCA caps were all the rage in the last 2 years or so. It caused a stir not only between the objectivist and subjectivist, but also amongst Cardas and Telos camps! We got many request for a shoot out but we never quite managed to do so, not until now that is. Now that Hi-Way Laser is the local dealer for Cardas, I managed to borrow a few from Kenny for the purpose of this interesting shoot out. Not only did I get the RCA caps but I also got the XLR male/female sets as well. And just for comparison's sake, I also threw in some generic nickel plated caps of China origin, I think. It's gonna be a wild ride from here on.

Since I have some Telos Platinum and Gold RCA caps already in use on my system, swapping them with the Cardas and generic caps was easy enough. However, to my very pleasant surprise, I have found that all 4 types of RCA caps gave different sonic cues, but they all did one thing sure, which is lowering the system's noise floor considerably. I hereby give you the subtle sonic characters brought about by the use of the 4 different RCA caps.
Cardas XLR caps on the left, vs Telos gold XLR caps on the right. Top view.

Bottom, note the Telos XLR caps has teflon insulation. Cardas on the left does without insulation.

First up is the generic nickel coated RCA caps. These caps are the cheapest one could find and they do bring down the noise floor of your system if all the un-used RCA input/outputs are covered. However, the lowered noise floor does come at a price. The sound takes a turn towards the darker end of the tonal palette, this is good for balancing overly bright or forward sounding systems. On more tonally balanced systems, the darkened effect also seemed to rob away some of the high frequency sheen, and "air". Transparency also drops a few notches if one uses too many of these. Use them only on RCA tape loops or monitor outs.

Next is the Telos gold RCA caps. Compared to the nickel coated generic caps, the Telos gold caps will also reduce noise floor, however, instead of darkening the sound field, they tend to highlight high frequency details and tonal contrast of the music. These are supremely musical caps to use, and I like them best used on the un used output RCAs of sources. Like my CD player has a variety of coax and other outputs and inputs which I do not use. The Telos gold caps are excellent for that purpose.

Following the Telos gold, is the Telos platinum RCA caps. These platinum coated caps are constructed the very same way as the gold caps, except the different finishing coating used. Sound wise, the Telos platinum RCA goes even further than the gold caps. The use of the platinum coated caps bring out even the lowest level of resolution buried within the musical mix. You can say they are most transparent among this group. However, when used in greater quantities, or should I say too many pairs employed, can result in the music take on an analytical quality. I had found it best to used the Telos platinum caps in the un used RCA inputs of the pre amp section.

Lastly, is the originator of RCA caps, from the Cardas stable. Visually, the Cardas RCA caps looks very similar to the generic nickel coated ones, but upon closer inspection, the material feels subjectively more dense and the finishing coating is of higher quality, on top of that, the Cardas "shell" logo is proudly silk screened on top, for a distinguished appearance. Noise floor reduction aside, I found the sound of the Cardas RCA caps to be the most balanced of the lot. It hasn't the darkness or the tendency for brightness, or an overly analytically quality. The mids seemed to take on more body and presence with the Cardas caps, which is excellent in the context of my system. The down side is however, if one should over use them, the Cardas RCA caps have a tendency to harden the high mid frequency range, which causes shouty mid range with some recordings. I like the Cardas best when used on the un used RCA outputs of my pre amp.
Top: All Telos gold and platinum caps used. Bottom: All Cardas caps used.

My Pass Labs X2.5 pre amp has lots RCA and XLR exposed jacks to cover. That allows me to have infinite RCA/XLR caps tweak options. Perfect for the hifi tweek geek.

The above sonic description of the RCA caps are also applicable to their XLR male/female counter parts. However, due to the inherent superior noise canceling properties of the XLR topology, the degree of effectiveness on gets from capping the un used inputs and outputs seems reduced compared to RCAs, making them offering less value for the money, dollar(or Ringgit if you wish) to sound wise. They do however work if one does wanna go the whole nine yards, like me. Telos offer XLR caps in choices of gold or platinum finishing, while Cardas offers only a standard finishing.
The Cardas caps prices. XLR male/female = RM$149/pair. RCA = RM$25/each.

My conclusion is that all the RCA/XLR caps have their pros and cons when it comes to sonic characteristics. All suffered from the same weakness, is that when too many of the same is used, it tends to over accentuate certain sonic attributes to the extreme which tips the balance towards negativity. Too much of a good thing? I don't know for sure.

What I am very sure is that I got the best results from playing around, with a few pairs of each. In other words, mix & match for best results. For example, I've found the Telos caps to promote high frequency details and when combined with the generic caps which tends to have a darkening effect on tonality, to create an effect of tonal shading and to add dynamic contrast for sculpting the sound stage. Throw in the Cardas to bring out the mid range slightly for some vocal presence enhancement and a more credible 3D staging and imaging illusion can be achieved.

Some of my friends also pointed out that they prefer to leave either the input exposed or just cap the outputs on the pre amp, for a more natural sound. In the context of their system, they felt capping all the un used inputs and outputs resulting in a sound stage that seems un naturally micro managed.

With that, I'd like to point out that your findings, based on the context of your system, may not agree with my conclusion above. I do think however, it's worth the patience and effort trying out to mix & match the RCA caps for best results.

Lastly, the usual YMMV caveat applies to this tweak. Go on and have some fun!

Also do read Odiosleuth's original review of the Telos caps dated 14th May 2009 for a refresher and pricing details. Click "Telos" on our right side bar to see it.

Cardas is sold by Hi-Way Laser, contact Kenny, tel: 019-2813399

Telos is sold by C&O Enterprise, contact John Sin, tel: 012-5269313


ShilaL_Kappler said...
This comment has been removed by a blog administrator.
tan said...

Hi Big E,

Very detailed and accurate reviews of those RCA caps, good works.

Eddie said...

Big E,

Very admire you have super ear!

mikelau.2 said...

Hi Big E,

Which of the 3 holes should the male protuding pin of the xlr cap be parked ? Does it make any difference ?

Big E said...

Tan, Eddie,

Thanks for the kind words. I have no super ears, but just a system transparent enough to let me hear the diferences.


The male XLR cap pin should go in to the positive signal, or hole 2.

However, you can use the logo silk screened on the caps as a guide. The pin should fit in to the hole when the logo points the right side up.

I did tried fitting the pin in to hole 3 of the XLR socket, just for fun, and it did sounded sound what muted. I very quickly removed it.

However, one should be carefull that the pin should NOT go in to hole labeled 1, as that is ground. If that happens, you may have unwittingly created a ground loop, which may result in a very loud "hum" noise.

Experiment with care is the word here.

peterson said...

Big E,

A you sure can listen the different?? who can prove?

tan said...

Hi Peterson,

I did hear differences with various brands/types of caps in my system too, that's why I agreed on BigE's reviews.
Like he said, your system must be transparent enough and I add that you need to have certain degree of listening skill, only then you will hear the differences.

peterson said...

I am sorry, but do you really think that hifi really is transparent? do you really think that you have such analytic capability? Do you have third party verifications for your claims?

This is like asking a question and providing an answer yourself to satisfy your own ego and then "teaching" others on your so call "knowledge".

I am sorry, but I am not against the product but, rather your claims.

I am sorry because I know I am rude. I like to apologize again for my rudeness. Thank you.

tan said...

Hi Peterson,

Never mind, there is no need to apologize, it's normal that you have such doubts about the claims.
I believe BigE also were just merely to share our experience rather than satisfying own ego and showing off our knowledge.
Yes, there is always a third party-my friend around during any auditions. As we are very fussy in sound, we confirm hearing differences.

kkthen said...

Some system can not plug any cap, it will make the system sound dead. My friend system with ayre cx7e + krell 400xi + sonus faber concerto domus can not use any single rca cap. We tried telos , cardas, unbranded plastic cap also cause same problem. Unlike my system, sound better with cardas & telos cap combination.

tan said...

Hi kkthen,

My system too, even with a single cap, would sound Too detailed and refined but sacrificing the body, depth and weight, overall sound so weird.

Capernaum Creative Solutions Inc. said...


If you are in the country, why not go and listen for yourself. Why depend on 3rd party approval. 3rd party verifications, no matter how valid, are still opinions.

In that respect, who do you deem are aurally trust worthy 3rd party?

David said...

Have you heard about the blind man feel elephant story??

Eddie said...

Sifu felix,

we have not seen your comments for a long time!I feel the reviews and comments of others are too subjective, too self centred,not neutral enough!Each one says he is right,they never can agree on anything!I wish to hear your comments on the caps!I hope you can give me my wish!

Eddie said...

Sifu felix,

we have not seen your comments for a long time!I feel the reviews and comments of others are too subjective, too self centred,not neutral enough!Each one says he is right,they never can agree on anything!I wish to hear your comments on the caps!I hope you can give me my wish!

Big E said...


Sorry to reply late. I've been away for a few days.

I anticipated questioning readers as I wrote this article. I do not ask readers to believe what I hear. However, there's no way for me to prove what I write, but to encourage readers to at least give the tweak in question a try on their own systems.

I liked the results I got from the tweak, but other readers have come to another conclusion, as demonstrated by kkthen and tan.

It is healthy to have diverse opinion in any hobby. Most important is that we share our findings.

Lastly, no need for appologies as I did not considered your question rude in anyway. Let's share and be merry, shall we?

unker vic said...

This is not to make matters more complicating( or maybe it does, I really can't foretell).

I used telos platinum on the rca 'jacks' at the back of my Cambridge amp(more than 20 years old in fact approaching 30 years). I liked the results and I left it as they are now. I also used a combination of telos platinum, gold and my own diyed version with each of my 6 subs in the multi sub system, again i like the results. Then again I don't expect others to like the same results I may like.

KK Then came to listen to my setup last week but I forgot to tell him I used the various caps on the rca inlets and outlets.

David said...

To all big sifu,

I think your have use blind test,please don't use eye liten,

David said...
This comment has been removed by the author.
unker vic said...

Would there be a need for blind test and not just 'eye listen', the answer is yes and no!

No, when one could perceived(as in one's mind eye)say the whole hi hat sound as a whole piece of metal piece with the zinnnggg sound with the plenty of caps plugged on, and compared with no caps at all, when the zinnngggg sound is all over the place and hardly could perceive the hi hat as 'occupying' a space in the soundstage! Then again some may ask how do we know it's the correct sound, or true to the recordings. You decide for yourself. If one rent a space to have a gig with your buddies, you may actually find the hi hat sound all over the place, so u want something true to live, then don't use the caps lor. You want to be able to enjoy the music without much strain on your concentration and no need to stretch on your imagination, nevermind if it's true to the recording or not, whether it's the correct sound or not, then u may want to use those caps.

BTW if u can't perceived any sound differences with and without the caps, then lucky u, u are going to safe lots of $$$$! No need to buy those caps la. Go buy more CDs to enjoy the music la.

monkey said...

WARNING!!! to everyone and to the OP: the OP's pin instruction/info is _woefully_ wrong. With Cardas XLR female caps--- the caps that have a single MALE PIN and which is used to cover the female XLR input--- the Cardas XLR pin goes into PIN 1 on the female XLR input (GROUND in std wiring scheme) and not not not not not not PIN 2 (HOT in std wiring scheme). basically, this poster has no idea what he's talking about. check it out. look it up. don't just trust me.

monkey said...

re: OP's pin assignment error- as below- RTFI re:pins and see that the blogger is a mook:

Big E said...


Wow! Thanks for pointing out my typo error more than 2 years later.

You're right, the correct connection for the Cardas XLR male caps with pin should go in to XLR connection 1 and NOT 2.

Please accept my appologies if you've found my posting misleading in anyway. The typo error is regretable.

Thanks for sharing your hifi knowledge on this blog.

It's learned readers like Monkey that keeps us on our toes. And we happily acknowledge there are plenty smart cookies here.

Rob Bertrando said...

Did you experiment with shorting vs. non-shorting caps on the RCA inputs?